Daylight film handling system

ABSTRACT

A system for enabling X-ray films, of the type primarily used in the dental and medical fields, to be handled in daylight for exposure to X-rays. The system utilizes identical film sheets emulsion coated on one or both faces, each sheet having a notch, displaced from the sheet center line, formed in one edge thereof. A stack of sheets is packed in an opaque envelope with the sheets being alternated so that all of the notches lie along a common stack edge arranged in two parallel rows, the notches in adjacent sheets lying in different rows. The system includes a light tight dispenser which receives the envelope and is capable of being operated to strip the envelope from the film sheet stack. The dispenser includes a pair of rotatable selector cams, each aligned with a different row of notches. A spring mounted back-up plate urges the film sheet stack against the selector cams with the two selector cams respectively bearing against notched and unnotched portions of the top sheet. Means are provided for alternately rotating the two cams so as to successively release the top sheet from the stack into a cassette removably engaged with the dispenser. The cassette includes parallel screens normally spring urged together in light tight relationship when disengaged from the dispenser. Engagement of the cassette with the dispenser in light tight relationship urges the screen plates apart to enable the released film sheet to fall therebetween. The cassette in turn operatively cooperates with a processor to enable the film sheet therein to be transferred to the processor.

United States atent Schmidt Feb. 5, 1974 DAYLlGHT FILM HANDLING SYSTEMily used in the dental and medical fields, to be handled [75] Inventor:Gunter Schmidt, Malibu, Calif. daylight for exposure to The Systemutilizes 1 identical film sheets emulsion coated on one or bothAssigneei Production, L08 g Califfaces, each sheet having a notch,displaced from the sheet center line, formed in one edge thereof. Astack [22] Flled' July 1970 of sheets is packed in an opaque envelopewith the PP 52,348 sheets being alternated so that all of the notcheslie along a common stack edge arranged in two parallel rows, the notchesin adjacent sheets lying in different iiiliii.35111131111113:ffffffii.ffffftl iifirows-Thesystemincludesalightflghtdisemwhich [58] Field of Search 271/6141 18 62 B 19 receives the envelope and is capable of being operated221/67 53/381 5 3 222/81 to strip the envelope from the film sheetstack. The

dispenser includes a pair of rotatable selector cams,

each aligned with a different row of notches. A spring [56] ReferencesCited mountectlh bacllr-up plate urgteils ltlhe film lsheet stackagainst e se ector cams wi t e two se ector cams UNITED STATES PATENTSrespectively bearing against notched and unnotched 2,342,571 2/1944Carroll R portions of the top sheet Means are provided for a]-ichwaflzer ternately rotating the two cams so as to successively 22069857/1940 2? 222/82 release the top sheet from the stack into a cassettere- 3287Ol2 11/1966 H8 R movably engaged with the dispenser. Thecassette in- 2:925:761 2/1960 Peary at a] n 221/67 x cludes parallelscreens normally spring urged together 2,704,075 3/1955 Cherkin 222/81in light tight relationship when disengaged from the 3,586,313 6/1971Ebeling 271/62 B x dispenser- Engagement of the cassette h t s- PrimaryExaminer-Even C. Blunk Assistant Examiner-Bruce H. Stoner, Jr.

Attorney, Agent, or Firm-Lindenberg, Freilich and Wasserman [57]ABSTRACT A system for enabling X-ray films, of the type primarpenser inlight tight relationship urges the screen plates apart to enable thereleased film sheet to fall therebetween. The cassette in turn.operatively cooperates with a processor to enable the film sheet thereinto be transferred to the processor,

ll Claims, 15 Drawing Figures PATENTED FEB 51974 3. 790.160

SHEU 2 0F 4 1 Gum-ER 5c/1M/07 BACKGROUND OF THE INVENTION The inventionrelates generally to a film handling system particularly useful forenabling the daylight handling of X-ray film sheets of the typeprimarily used in the dental, medical and industrial fields.

In the conventional use of X-ray films, as by dental and medicaltechnicians, an X-ray film sheet is normally loaded into a cassette in adarkroom, exposed with the patient and then again taken into thedarkroom for removal from the cassette for processing. The necessity ofdarkroom handling of the X-ray film is inconvenient, time-consuming, andcostly.

OBJECTS AND SUMMARY OF THE INVENTION An object of the present inventionis to provide a film handling system which enables a film sheet to beloaded into acassette and transferred from the cassette to a processorin daylight without inadvertently exposing the film.

Briefly, in accordance with the preferred embodiment of the presentinvention, standard X-ray film sheets are all notched on one edge priorto packaging in a light tight envelope. The notches are all spaced froma center line normal to the edge so that when a plurality of sheets arestacked with the orientation of successive sheets being alternated, thenotches lie in two rows all along a common edge of the stack. Thus, in astack of one hundred sheets for example, the 50 odd sheets will havenotches lying in one row, while the 50 even sheets will have notcheslying in the other row. The stack of sheets is packed in a light tightenvelope.

In accordance with a significant feature of the present invention, alight tight dispenser is provided for storing the film sheet stack. Thedispenser is capable of being operated to strip the envelope from thestack and to then dispense one sheet at a time from the stack.

In accordance with a further significant aspect of the invention, sheetsare dispensed one at a time by alternately rotating a pair of filmselector cams adapted to bear against the stack in alignment with thetwo rows of notches to thus free the top sheet from the stack when onecam moves out of engagement therewith and the other cam moves intoalignment with the notch thereof.

In accordance with still a further aspect of the invention, a removablecassette is provided for cooperating with the dispenser to enable it toreceive a film sheet released from the dispenser without exposing thefilm sheet to light. Preferably, operation of the film selector cams isprevented unless the cassette is in proper position to receive adispensed film sheet. In accordance with another feature of theinvention, means are provided for indicating when a film sheet isdispensed from the dispenser and when a film sheet is present in thecassette.

In accordance with a still further aspect of the invention, a processoris provided for operatively cooperating with the cassette to enable afilm sheet to be easily transferred from the cassette to the processorwithout exposing it to ambient light.

The novel features of the invention are set forth with particularity inthe appended claims. The invention will be best understood from thefollowing description when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary plan viewpartially illustrating a stack of X-ray film sheets notched inaccordance with the present invention;

FIG. 2 is an isometric view of a film package in accordance with thepresent invention;

FIG. 3 is an isometric view of a dispenser apparatus constructed inaccordance with the present invention;

FIG. 4 is an enlarged fragmentary sectional view taken substantiallyalong the plane 44 of FIG. 3

showing the film sheet stack resting on a pair of package support bars;

FIG. 5 is a sectional view similar to FIG. 4 illustrating the film stackin dispensing position resting on a pair of film selector rods;

FIG. 6 is an enlarged plan view illustrating the gear train foralternately driving the film selector cam;

FIG. 7 is a side view of a film selector cam particularly illustratingits taper;

FIG. 8 is an isometric view partially broken away illustrating a filmX-ray cassette in accordance with the present invention;

FIG. 9A is an enlarged sectional view taken substantially along theplane 9A-9A of FIG. 8 illustrating the position of a spacer plate whenthe screens of the cassette are closed;

FIG. 9B is an enlarged sectional view taken substantially along theplane 9B-9B of FIG. 8 illustrating the relationship of the screen plateswhen the cassette is closed;

FIG. 9C is an enlarged sectional view corresponding to FIG. 9Aillustrating the position of the spacer plate when the cassette isengaged with the dispenser pins to thus open the cassette and space thescreen plates from one another;

FIG. 9D is a sectional view corresponding to FIG. 9B illustrating thecassette screen plates spaced apart from one another;

FIG. I0 is a plan view of a cassette spring cover plate in accordancewith the present invention;

FIG. 11 is a sectional view taken substantially along the plane Ill-llof FIG. 10; and

FIG. I2 is an isometricillustration showing the cassette in operativerelationship with a processor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Attention is now called to FIG.I which constitutes a fragmentary plan view showing the bottom edge of astack of rectangular X-ray film sheets notched in accordance with thepresent invention. More particularly, in the preferred embodiment of thepresent invention, all of the film sheets 20 are notched along a commonstack edge 22 with the notches being spaced from a center line 24extending normal to the edge 22. All of the sheets 20 are notchedidentically, i.e., with a notch 26 being formed in the edge 22 at acertain spacing, d, from the center line 24. The film sheets 20 arestacked with the orientation of successive sheets being alternated sothat the notches 26 all lie along a common stack edge 22 but arranged intwo rows 28 and 30 equally spaced from the center line 24. Thus, in astack of film sheets, for example, the 50 odd sheets in the stack willhave a notch 26 aligned with the row of notches 28. The 50 even sheetswill each have a notch 26 aligned with the row of notches 30.

In accordance with the present invention, a stack of film sheets,notched as shown in FIG. 1 is inserted into an opaque envelope 32 asshown in FIG. 2. Preferably, the envelope 32 is formed of opaque blackplastic material and has a length exceeding the length of the filmsheets 20. More particularly, the envelope 32 is preferably madesufficiently long so that its leading and trailing ends 34 and 35 canloosely extend beyond the leading and trailing edges 36 and 37 of thefilm sheet stack when the stack is contained within the envelope. Theenvelope is preferably heat sealed along line 38 and its bottom edge 39.A hole 40 is provided in the leading end 34 of the envelope and theenvelope is preferably sealed around the hole 40.

Attention is now called to FIG. 3 which illustrates a dispenser,particularly adapted to function with the specially packaged film sheetsshown in FIGS. 1 and 2, for dispensing film sheets one at a time, into acassette in daylight without inadvertently exposing the film sheets tolight. More particularly, a dispenser 54, as shown in FIG. 3, isprovided in accordance with the present invention for the purpose ofinitially stripping the envelope 32 from the stack of film sheetscontained therein and to thereafter dispense one sheet at a time fromthe stack into a cassette adapted to be operatively supported beneaththe dispenser exit opening 56.

The dispenser 54 is comprised of a housing 57 having a film packagecompartment 58 defined therein between side walls 60 and 62, and betweenback wall 64 and slide door 66. The door 66 is provided to permit accessto the film package compartment and to prevent light from seepingtherein when the door is closed. The plane of the door 66 is spacedsufficiently from the back wall 64 to contain the film sheet stacktherebetween.

A bar 70 is supported within the housing 54 between side walls 60 and 62and close to the top of the housing 57. The bar is mounted for rotationabout its axis under the control of a manual crank 72 extendingoutwardly from the housing side wall 62. Means are provided on the bar70 to permit the leading end of envelope 32 to be secured thereto inorder to enable the envelope to be stripped from the film sheet stack;Thus, the bar 70 may be provided with a hook adapted to thread the hole40 in the envelope or it may merely be bifurcated, as illustrated, toreceive the envelope leading end between the two portions thereof. Itwill be appreciated that many alternative arrangements could also beemployed to releasably secure the leading end 34, of the envelope 32 tothe rotatable bar 70.

In order to enable the envelope 32 to be stripped from the stack of filmsheets 20, a door 80 (FIG. 4) is provided carrying a manually actuatablecutting blade therein. The door 80 is hinged about axis 81 extendingbetween side walls 60 and 62. The door 80 supports a cutting blade 82therein mounted for reciprocal movement in the plane of the door. Ahandle 83 is carried on the upper edge of the cutting blade. The bladeis spring urged upwardly (by means not shown), so that its lower cuttingedge 85 is normally contained within the profile of the door 80. Anotched cutting bar 84 is fixedly mounted between the walls 60 and 62beneath the blade 82 cutting edge 85.

A pair of stack support bars 86, 88 are contained within the filmpackage compartment projecting forwardly from the back wall 64. Thestack support bars each terminate at their forward end in an upwardlyextending flange 90.

In the use of the portion of the dispenser apparatus thus far described,with the sliding door 66 open, the leading end of the envelope 32 ispassed between the portions of the bifurcated bar and the bar 70 isrotated through perhaps one turn to secure the envelope thereto. Thefree trailing end 35 of the envelope 32 is inserted between the cuttingbar 84 and the lower edge of the door as shown in FIG. 4. This insertionis of course facilitated by initially swinging the door 80 out of theway about hinge axis 81. After the envelope trailing end has beeninserted between the door 80 and the cutting bar 84, the door isreturned to the position shown in FIG. 4. The envelope trailing end isthen cut by manually forcing the cutting bar downwardly. The slidingdoor 66 is then closed to light seal the film package compartment.Rotation of the crank 72 then pulls the envelope 32 vertically upwardstripping it from the film sheet stack.

The stack support bars 86 and 88 are pivotally secured at their rearends to a channel member 92 for rotation about spindles 94 carried bythe channel member. The channel member 92 is mounted for linear verticalmovement and has a rack 98 mechanically se' cured thereto. The rack 98is engaged with a pinion 100 which is operatively coupled to crank 102(FIG. 3) extending out of the housing. Rotation of the crank 102 rotatesthe pinion 100 .to in turn move the rack 98 therepast to thus slide thechannel member 92 downwardly from the position shown in FIG. 4. Each ofthe stack support bars has a follower pin 103 secured thereto. Eachfollower pin extends through a slot 104 formed in a plate 105 fixedlymounted in the housing. The slot 104 is comprised of a substantiallyvertical portion 106 and a rearwardly directed portion 107. With thechannel member 92 in its upper position shown in FIG. 4, the followerpin 103 will be accommodated in slot portion 106 and as a consequence,the bars 86 and 88 will extend forwardly in a substantially horizontalplane. As the channel member 92 is moved downwardly by rotating crank102, the follower pins 103 will move into slot portion 107 so as topermit the bars 86, 88 to pivot downwardly out of the way as illustratedin FIG. 5.

With continuing reference to FIGS. 4 and 5, it is pointed out that apressure plate 110 is provided which is supported for pivotal movementon a pair of hinge pins 112 fixedly mounted in the dispenser housing. Aspring 114 bears against the back of plate 110 tending to pivot it in aclockwise direction about hinge pins 1 12. A rearwardly projecting arm116 is secured to the plate 110 and carries a roller follower 118 ridingon a cam surface 120. The cam surface 120 is formed on the lower end ofthe rack 98. When the channel member 92 and rack 98 affixed thereto arein their upper position shown in FIG. 4, then the roller follower 118 isforced rearwardly to hold the pressure plate 110 in a substantiallyvertical orientation. It is pointed out that a recess 121 is formed onthe lower surface of the rack 98. A latch member 122 is adapted toengage the rack in the recess 121 to hold the rack in the upper positionof FIG. 4. The latch is mounted on a rod 123 extending from the housingand selectively rotatable by the user to enable him to disengage thelatch and rack to then permit him to lower the rack to the position ofFIG. 5 by rotating crank 102.

As can be seen from FIG. 5, when the crank 102 is turned to move therack 98 downwardly, the follower 118 will ride up the cam surface 120 toenable the spring 114 to pivot the plate 110 clockwise about hinge pin112 to thus resiliently urge the film pressure plate 110 forwardly.

A pair of film selector cam rods 130 and 132 are mounted for rotationabout their own axes beneath the stack support bars 86, 88 positioned asillustrated in FIG. 4. The rods 130 and 132 respectively carry cams 134and 136 at their forward ends. As is best shown in FIG. 6, the cams 134and 136 are essentially triangularly shaped and eccentrically mounted onthe rods 130 and 132. That is, the rods connect to the cams essentiallyat the apex thereof with the major portion of the cam surface extendingperpendicular to and beyond the rod. Prior to considering the manner inwhich the rods are mounted to effect the alternate rotation thereof,attention is called to FIG. 5, wherein it will be noted that when thechannel member 92 is lowered from the position shown in FIG. 4, to theposition shown in FIG. 5, by rotation of the crank 102, the film stackwill be correspondingly lowered as the stack support bars 86 and 88 movedownwardly, so that as the bars 86 and 88 move past the rods 130 and132, the film stack will be deposited on the rods 130 and 132 as shownin FIG. 5. Concurrently with the downward movement of the stack supportbars 86 and 88, the film pressure plate 110 will move forward as hasbeen already discussed, to urge the film stack against the cams 134 and136.

In order to facilitate the proper retention of the stack against thepressure plate 110, a plurality of arms are provided to bear against thestack. More particularly, an upper arm 138 is provided having a flangedforward end 139. The arm 138 is pivoted about pin 140 secured in a shortchannel member 141. The channel member 141 is mounted for linearvertical movement in the housing in alignment with channel member 92 sothat when the channel member 92 is up, it holds channel member 141 up.When the channel member 92 is lowered from the position shown in FIG. 4to the position shown in FIG. 5, channel member 141 correspondinglyfalls. As can be seen in FIG. 4, when the channel member 1411 is in itselevated position, the end of arm 138 rearwardly of pin 140 is engagedwith the stop 142 so as to hold the arm 138 pivoted clockwise. With thearm positioned as shown in FIG. 4, adequate clearance is provided toinsert the film package against the pressure plate 1111. When thechannel member 92 is lowered, channel member 141 will be correspondinglylowered to permit the arm 138 to pivot counter clockwise so that theflanged forward end engages the front film sheet.

In addition to the arm 138, a pair of arms 143 and 144 are provided forbearing against the film sheet stack to prevent it from buckling fromits own weight. More particularly, the arms 143, 144 are hinged aboutpins 145 fixedly mounted in the housing. The arms are provided withorthogonally oriented front terminal stubs 146, adapted to bear againstthe front film sheet. A rear end 147 of the arm extends beyond the hinge145 and is coupled to a link 148. Thus, when the link 148 is raised, thearms 143, 144 are pivoted clockwise thus moving the stubs 146 out ofengagement with the film sheet stack. On the other hand, when the link148 is pulled downwardly, the arms 143, 144 are pivoted counterclockwise to engage the stubs with the film sheet stack. As will beexplained in greater detail hereinafter, the link 148 is coupled to acassette tray mechanism so that when there is no cassette in position toreceive a dispensed film sheet, the stubs bear against the film sheetstack to prevent buckling. When a cassette is moved into position toaccept a dispensed film sheet, the stubs 146 are moved out of engagementwith the stack to permit a sheet to be released therefrom.

The film selector cam rods 130 and 132 are positioned so as to bealigned with the two rows of notches 28, formed in the lower edge 22 ofthe film sheet stack. As will be seen hereinafter, the cams 134 and 136will be alternately rotated by actuation of the gear train of FIG. 6. Asingle rotation of one of the cams will release the top sheet from thefilm sheet stack. That is, the top sheet in the film stack will have anotch lying either in the first or second row of notches. Assume forexample, that the top sheet in the stack has a notch in alignment withcam 134. This means that cam 136 will be bearing against an unnotchedportion of the sheet. When the gear train of FIG. 6 is actuated, it willrotate cam 136 to move it out of engagement with the top sheet. Inasmuchas the dimensions of the notches are larger than the correspondingdimensions of the cams 134 and 136, there will no longer be anythingbearing against the top sheet and it will therefore effectively 30 jumpout from the stack with the notch therein passing over the cam 134. Thecam 134 of course, will how ever, be bearing against the next sheet inthe stack so that only one sheet at a time will be released from thestack.

In order to understand why the released top sheet effectively jumps outfrom the stack beyond the cam, it is pointed out that when the cams 134and 136 are bearing against the stack of film sheets, that althoughthere may be sheets in the stack, there only will be the thickness of 50sheets in alignment with the notched rows. That is, cam 134 will behearing against only 50 sheets since fifty of the sheets will be notchedin alignment therewith. Similarly, cam 136 will only be bearing against50 sheets. However, since there are twice that many sheets in the stack,the cams will somewhat buckle the sheets adjacent to the notched areas.This effect is desirable because as a consequence, when the cam bearingagainst the top sheet moves out of the way, the pressure release againstthe top sheet enables the top sheet to jump forwardly due to theinherent resiliency of the sheet.

FlG. 6 illustrates the gear train for rotating the rods 131) and 132alternately. The gear train of FIG. 6 includes a main gear 150 havingteeth extending halfway around its circumference. The main gear 150 ismounted on a shaft 152 in common with a gear 154 engaged with a sprocketchain 156. The sprocket chain is preferably driven by a motor butalternatively can be driven by a manual crank. The gear ratios areselected so that a single actuation of the drive motor or one fullrotation of the manual crank causes the gears 150 and 154 to rotatethrough one half turn.

The teeth extending halfway around the circumference of gear 156 areengagable with the circumferential teeth on gears 160 and 162. Each ofthe gears 160 and 162 is provided with a keyway 164 for accommodating aspring detent 166.

When the gear 150 is rotated one half turn in a clockwise direction fromthe position shown in FIG. 6, the gear 162 will be rotated one fullturn. During this action, the gear 160 will not be rotated. However,when the gear 150 is rotated through another half turn, the gear 160 isrotated one full turn while the gear 162 remains idle. Thus, it shouldbe appreciated that the gears 160 and 162 will be alternately rotated asthe drive motor or crank is turned. Gear 162 is coupled via gears 168and 170 to film selector cam rod 132 which drives cam 136. Gear 160 iscoupled via gears 172 and 174 to film selector cam rod 130 which carriescam 134.

It is to be noted that in FIG. 7 the cams 134 and 136 are shaped so asto define a narrow leading edge to assure, in the rotation thereof, thatthe leading edges approach the stack outwardly of the top sheet thereof.The center portion 178 of the cam is thickened to increase the bearingengagement of the cam against the film sheet stack.

Attention is now called to FIGS. 8-11 which illustrate a film sheetcassette intended to be used in cooperative relationship with thedispenser 54 of FIG. 3. More particularly, the cassette 56 is intendedto be mounted beneath the dispenser 54 so as to accept therefrom onefilm sheet at a time as dispensed from the dispenser. The cassette 56 iscomprised of a frame having a screen plate back wall 200 as well as sidewalls 202 and 204 and a bottom wall 206 extending upwardly therefrom. Aspring equipped cover plate 208 is provided for being received over thescreen plate 200. More particularly, the walls 202 and 204 are providedwith cut out portions 210 for accommodating ears 212 provided on thecover plate 208. Aligned holes are provided in both ears 212 and cut outportions 210 for receiving screws for fastening the plate 208 to thecassette frame in opposition to the back screen plate 200. A pluralityof U-shaped springs 218 are secured to the cover plate 208. Moreparticularly, the bight portion 220 of the springs are secured to theplate with the spring leg portions extending towards the screen plate200 and adapted to bear against an intermediate screen plate 224.

A channel 226 is formed in the side wall 202 while a channel 228 isformed in the side wall 204. A spacer plate 230 is mounted within thechannel 228 for sliding movement therealong. The spacer plate 230 isprovided with a plurality of ramp portions 232 along the length thereof.The screen plate 224 is provided with a plurality of studs 234 extendingtherefrom which rest on the ramps 232. FIG. 9A illustrates the stud 234at the bottom of the ramp 232 formed in the spacer plate 230. By slidingthe spacer plate 230 downwardly, as shown in FIGS. 9A and 9C, the stud234 will ride up the ramp 232 to thus substantially increase the spacingbetween the screen plate 224 and screen plate 200.

In order to prevent light from entering the cassette, a light shield isprovided comprised of a flange 233 formed on the upper edge of screenplate 224 adapted to cooperate with a slotted flexible sealing member234 secured to the screen plate 200. That is, when the cassette isclosed as shown in FIGS. 9A and 9B, the flange 233 projects into theslot 235 in the sealing member 234 to prevent light from enteringtherebetween. When the spacer plate 230 is moved downwardly to spreadapart the screen plates, the flange 233 is, of course, withdrawn fromthe slot 235 to permit a film sheet to pass therebetween. In order tofacilitate the entry and exit of a film sheet into and from thecassette, the edge surfaces 236, 237 of the sealing member 234 arebeveled. In addition, a bevel member 238 is provided adjacent the flange233 to facilitate entrance of a film sheet into the cassette and bevelmembers 239 are provided on the opposite side of the flange forprojecting through openings 240 in the screen plate 224 to facili tateexit of a film sheet from the cassette.

In accordance with the present invention, a pair of depending pins 241and 242 (FIG. 3) are provided on the dispenser, adjacent the exitopening 56, for extending into the channels 226 and 228 to slide thespacer plates 230 and thus open the spacing between the screen plates224 and 200.

In order to load a cassette into position to receive a dispensed filmsheet, the cassette is placed in tray 243 secured to arms 244. The arms244 are coupled to a rod 245 terminally secured to a link 246 fixedlysecured to shaft 247. The shaft extends externally of the housing and iscoupled to crank 248. Thus, by turning the crank 248, the link 246 willbe rotated to raise the tray 243 to position a cassette therein adjacentthe dispenser exit opening 56. In raising the cassette to the exitopening 56, the cassette will engage pins 241 and 242 to open thecassette and permit it to receive a dispensed film sheet, as haspreviously been described.

In order to assure that no light enters the dispenser housing, a lightshield is provided therein consisting of a finger 249 pivoted on one endabout pin 250 and engaged on the other end with a slidably mounted plate251. As the cassette is raised, it engages the bevel surface of finger249 and pivots it clockwise to slide the plate 251 to the right. Theslide plate 251 has a slot 252 therein adapted to align with slot 253 ina fixed plate to permit a dispensed film sheet to fall therethrough. Anadditional light shielding hinge plate 254 is preferably mounted beneaththe slide plate 251. Thus, as the cassette is raised into position forreceiving a dispensed film sheet, both the cassette and dispenser lightshields are automatically opened. Preferably, the raising of thecassette also closes a switch (not shown) to actuate a motor to operatethe gear train of FIG. 6 to thus release a film sheet into the cassette.A spring urged bell crank 255 is preferably provided for urging thecassette forwardly to facilitate removal of the cassette from the tray.

An indicator is provided on the dispenser to indicate the dispensing ofa film sheet from the stack into the cassette. In its simplest form, theindicator constitutes a lever 256 pivoted somewhere intermediate itsends. The inner end of the lever 256 is positioned so as to be engagedby the falling film sheet to thus pivot the outer end of the leverupwardly to expose a flag 257 carried thereby in an indicator window258. The cassette is preferably also provided with an indicator 259 forindicating when a film sheet is present in the cassette even after thecassette has been removed from the dispenser. The indicator 259 includesa window 258 through which a flag 261, carried by a lever 262 can beseen. If the cassette contains a film sheet, the sheet will bear againstthe lever showing the flag 261 through the window 258. With the cassetteremoved from the dispenser, the springs 218 will lock the film sheet,thus causing the indication to be held as long as the film sheet remainsin the cassette.

In the use of the film dispensing apparatus in accordance with theinvention, a film package as shown in FIG. 2, is placed into thedispenser against the pressure plate 110. This is done, of course, withthe channel member 92 in the raised position as shown in FIG. 4, withthe arm 138 raised and out of the way and with the stack support bars 86and 88 in position for supporting the film package. Additionally, inorder to facilitate the loading of the film package into the dispenser,the cassette tray 243 is preferably raised, without the cassettetherein, in order to raise the links 148 and move the stubs 14boutwardly from the pressure plate 110. The leading end of the filmpackage envelope is then engaged with the bar 70 and the trailing end ofthe envelope is passed between the hinged door 80 and the cutting bar84. The blade handle 83 is then forced downwardly to cause the blade 85to sever the trailing end of the envelope. The housing door 66 is thenclosed and the crank 72 rotated to strip the envelope from the filmsheet stack. Subsequently, the crank 102 is rotated to lower the channelmember 92 and deliver the film sheet stack onto the cam rods 130 and132. In so doing, the pressure plate H is permitted to move forwardlyunder the pressure of spring 114 to urge the film sheets against thecams 134 and 136. The cassette tray is lowered to move the stubs 1146into engagement with the front sheet of the stack to prevent buckling.The dispenser apparatus is then ready for dispensing a film sheet into acassette. A user will place a cassette into the tray Mid and then raisethe cassette by rotating crank 248. This action will lift the stubs 146from the stack. Additionally, as the cassette is raised into thedispenser exit opening, the dispenser light shield and cassette lightshield both open. Further, the cassette will engage a switch to actuatea drive motor to operate the gear train of FIG. 6 to thus release asingle sheet from the stack which will then free fall into the opencassette therebelow.

It will be recognized that in accordance with the foregoing procedureand apparatus, a technician is able to load a film sheet into thecassette in daylight without inadvertantly exposing the film sheet tolight. With the film sheet in the cassette, the film sheet can then beexposed with the patient. Thereafter, as shown in FIG. 12,-

the cassette can be used to release its exposed film sheet into aprocessor 260 in daylight without inadvertantly exposing it. That is,the processor includes upwardly projecting pins for engaging the spacerplates 230 within the cassette so as to space the screen plates 224 and200 from one another to thereby enable the film sheet within thecassette to fall into the processor.

From the foregoing, it should be recognized that a system has beendisclosed herein for enabling X-ray film sheets primarily of the kindused in the dental and medical fields to be handled exclusively indaylight thus eliminating the costly and cumbersome procedure of loadingand unloading film sheets into a cassette in the darkroom only.

What is claimed is:

l. A dispenser apparatus useful for dispensing film sheets, each havinga notch extending inwardly from an edge thereof, one at a time from astack of such sheets, said stack being comprised of alternate odd andeven sheets with the notch in all of said odd sheets being aligned in afirst row and the notch in all of said even sheets being aligned in asecond row, said dispenser apparatus comprising:

a housing adapted to accommodate said stack;

first cam means in said housing for engaging said stack in alignmentwith said first row of notches, said first cam means comprising a firstcam member eccentrically secured to a first rotatable rod;

second cam means in said housing for engaging said stack in alignmentwith said second row of notches, said second cam means comprising asecond cam member eccentrically secured to a second rotatable rod; and

means for alternately rotating said first and second rods foralternately disengaging said first and second cam means from said stackto successively release one sheet at a time therefrom.

2. The dispenser apparatus of claim 1 wherein said housing comprises alight tight housing including a film sheet exit opening; and

means in said housing for supporting said stack with said sheetssubstantially vertically oriented.

3. The dispenser apparatus of claim 1 wherein the dimensions of saidfirst and second cam means projected upon said stack are less than thecorresponding dimensions of said notches; and including spring means forurging. said stack and cam means into engagement.

4. The dispenser apparatus of claim ll wherein said first and secondrotatable rods extend substantially parallel to one another in a commonplane and are adapted to support said stack along one edge thereof.

5. The apparatus of claim 1 including a plate adapted to bear againstsaid stack; and

spring means coupled to said plate for resiliently urging said stackagainst said first and second cam means.

6. The apparatus of claim 5 including at least one arm positioned tobear against said stack for retaining said stack against said plate.

7. The apparatus of claim 6 including means for selectively holding saidarm away from said plate for facilitating placement of said stackthereagainst.

8. An apparatus useful together with a film package comprised of a stackof film sheets contained within an envelope having a first end thereofextending beyond one edge of said stack, for removing said envelope fromsaid stack without exposing said film sheets to light, said apparatuscomprising:

light tight housing means adapted to accommodate said film packagetherein in a substantially vertical orientation with the part of saidenvelope extending beyond said stack disposed uppermost;

a rotatable bar disposed in said housing means;

means carried by said bar for engaging said first end of said envelopeextending beyond said stack; means disposed outside of said housing forrotating said bar to lift said envelope from said stack;

first and second support arms disposed within said housing means forsupporting said film package; first and second rods extending parallelto one another in a common plane disposed within said housing meansbelow said support arms and means for lowering said support arms fortransferring said stack to said first and second rods.

9. The apparatus of claim 8 wherein said stack is comprised ofalternated odd and even sheets, each of said odd sheets having a notchdefined therein along a first row and each of said even sheets having anotch defined therein along a second row, said first and second rowsbeing located so as to enable them to be respectively aligned with saidfirst and second rods, re-

spectively;

a first cam member carried by said first rod for engaging said stack inalignment with said first row of notches; and

a second cam member carried by said second rod for engaging said stackin alignment with said second row of notches.

10. The apparatus of claim 9 wherein said first and second cam memberseach have substantially a triangu- 1Q lar outline projected upon saidstack and dimensions cam members from said stack.

1. A dispenser apparatus useful for dispensing film sheets, each havinga notch extending inwardly from an edge thereof, one at a time from astack of such sheets, said stack being comprised of alternate odd andeven sheets with the notch in all of said odd sheets being aligned in afirst row and the notch in all of said even sheets being aligned in asecond row, said dispenser apparatus comprising: a housing adapted toaccommodate said stack; first cam means in said housing for engagingsaid stack in alignment with said first row of notches, said first cammeans comprising a first cam member eccentrically secured to a firstrotatable rod; second cam means in said housing for engaging said stackin alignment with said second row of notches, said second cam meanscomprising a second cam member eccentrically secured to a secondrotatable rod; and means for alternately rotating said first and secondrods for alternately disengaging said first and second cam means fromsaid stack to successively release one sheet at a time therefrom.
 2. Thedispenser apparatus of claim 1 wherein said housing comprises a lighttight housing including a film sheet exit opening; and means in saidhousing for supporting said stack with said sheets substantiallyvertically oriented.
 3. The dispenser apparatus of claim 1 wherein thedimensions of said first and second cam means projected upon said stackare less than the corresponding dimensions of said notches; andincluding spring means for urging said stack and cam means intoengagement.
 4. The dispenser apparatus of claim 1 wherein said first andsecond rotatable rods extend substantially parallel to one another in acommon plane and are adapted to support said stack along one edgethereof.
 5. The apparatus of claim 1 including a plate adapted to bearagainst said stack; and spring means coupled to said plate forresiliently urging said stack against said first and second cam means.6. The apparatus of claim 5 including at least one arm positioned tobear against said stack for retaining said stack against said plate. 7.The apparatus of claim 6 including means for selectively holding saidarm away from said plate for facilitating placement of said stackthereagainst.
 8. An apparatus useful together with a film packagecomprised of a stack of film sheets contained within an envelope havinga first end thereof extending beyond one edge of said stack, forremoving said envelope from said stack without exposing said film sheetsto light, said apparatus comprising: light tight housing means adaptedto accommodate said film package therein in a substantially verticalorientation with the part of said envelope extending beyond said stackdisposed uppermost; a rotatable bar disposed in said housing means;means carried by said bar for engaging said first end of said envelopeextending beyond said stack; means disposed outside of said housing forrotating said bar to lift said envelope from said stack; first andsecond support arms disposed within said housing means for supportingsaid film package; first and second rodS extending parallel to oneanother in a common plane disposed within said housing means below saidsupport arms and means for lowering said support arms for transferringsaid stack to said first and second rods.
 9. The apparatus of claim 8wherein said stack is comprised of alternated odd and even sheets, eachof said odd sheets having a notch defined therein along a first row andeach of said even sheets having a notch defined therein along a secondrow, said first and second rows being located so as to enable them to berespectively aligned with said first and second rods, respectively; afirst cam member carried by said first rod for engaging said stack inalignment with said first row of notches; and a second cam membercarried by said second rod for engaging said stack in alignment withsaid second row of notches.
 10. The apparatus of claim 9 wherein saidfirst and second cam members each have substantially a triangularoutline projected upon said stack and dimensions less than thecorresponding dimensions of said notches; and spring means for urgingsaid stack and cam members into engagement.
 11. The apparatus of claim10 wherein said first and second cam members are eccentrically mountedon said first and second rods; and including means for alternatelyrotating said first and second rods to alternately disengage said firstand second cam members from said stack.